1. Field of the Invention
This disclosure generally relates to methods for making integrated circuit components, and more particularly, to making three-dimensional (3D), metal-insulator-metal (MIM) capacitors upon or within associated substrates.
2. Related Art
MIM capacitors can be provided on semiconductor chips having active circuit elements, i.e., “active chips,” or on passive chips containing passive circuit elements, such as capacitors, inductors, resistors, etc., for subsequent mounting to active chips.
Conventional capacitors made in, e.g., a silicon substrate, can be of two general types. A first type can be used, e.g., to store charge for each bit in a dynamic random access (DRAM) chip. A second type can be used for “decoupling” applications, wherein the primary focus has been on “planar” or so-called “two-dimensional” (2D) capacitors made on or in passive substrates and having very thin alternating dielectric and electroconductive layers, in single or multi-layer formats. Both types of capacitors can have limitations, e.g., low capacitance densities and low quality factors (i.e., efficiencies).
Methods for making capacitors in “blind” or “through” vias or trenches in substrates that overcome some of these drawbacks of the prior art are described in commonly owned U.S. Pat. No. 8,502,340 to V. Oganesian et al., the entire disclosure of which is incorporated herein by reference. These “three-dimensional” (3D) “via” or “trench” capacitors can achieve higher capacitances due to the relatively larger surface areas of their sidewalls, but can be difficult to coat with metal/dielectric layers with uniformly conformal coverage due primarily to limited mass transport into trenches or vias that are relatively deep and/or narrow.
Accordingly, a need exists for methods for making capacitors on or in associated substrates that achieve substantially higher capacitances than conventional 2D capacitors, but within which the MIM layers are substantially easier to form than in conventional via- or trench-type capacitors.